Kost R, Jones D, Isfort R, Witter R, Kung H J
Department of Molecular Biology and Microbiology, Case Western Reserve University, School of Medicine, Cleveland, Ohio 44106.
Virology. 1993 Jan;192(1):161-9. doi: 10.1006/viro.1993.1018.
We recently reported the phenomenon of retroviral insertion into a herpesvirus (Isfort et al., (1992) Proc. Natl. Acad. Sci. USA 89, 991-995). We have now isolated Marek's disease virus (MDV) clones that carry retroviral inserts. Retroviral LTR insertion has the potential to activate or inactivate herpesvirus genes leading to alterations of the biological properties of the herpesviruses. The structure and the expression pattern of a virus clone carrying a solitary LTR insertion was characterized in detail. The LTR insertion is accompanied by deletions in the herpesvirus genome at each of the junctions of the short unique region (US) and its inverted repeats (RS). This results in a significantly truncated RS region. Despite these structural rearrangements, the virus is replication-competent and demonstrates an enhanced growth rate in vitro. While the MDV homologs of herpes simplex US genes are retained in this virus, at least two open reading frames are deleted and one transcript observed in wild-type virus is disrupted. In addition to defining several regions of MDV that are nonessential for in vitro growth, this clone illustrates one way in which retroviral information can be stably transmitted by a herpesvirus.
我们最近报道了逆转录病毒插入疱疹病毒的现象（伊斯福特等人，（1992年）《美国国家科学院院刊》89卷，991 - 995页）。我们现已分离出携带逆转录病毒插入片段的马立克氏病病毒（MDV）克隆。逆转录病毒长末端重复序列（LTR）插入有可能激活或失活疱疹病毒基因，从而导致疱疹病毒生物学特性的改变。对一个携带单个LTR插入的病毒克隆的结构和表达模式进行了详细表征。LTR插入在短独特区域（US）与其反向重复序列（RS）的每个连接处都伴随着疱疹病毒基因组的缺失。这导致RS区域显著截短。尽管有这些结构重排，该病毒仍具有复制能力，并在体外显示出增强的生长速率。虽然单纯疱疹病毒US基因的MDV同源物在这种病毒中得以保留，但至少有两个开放阅读框被删除，并且在野生型病毒中观察到的一个转录本被破坏。除了确定MDV中几个对体外生长非必需的区域外，该克隆还说明了逆转录病毒信息可以通过疱疹病毒稳定传递的一种方式。
